[ICE]: rustdoc: Deref impl without Target type #156484

warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
 --> code.rs:1:12
  |
1 | #![feature(specialization)]
  |            ^^^^^^^^^^^^^^
  |
  = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
  = help: consider using `min_specialization` instead, which is more stable and complete
  = note: `#[warn(incomplete_features)]` on by default


thread 'rustc' (3512757) panicked at src/librustdoc/passes/collect_trait_impls.rs:169:18:
Deref impl without Target type
stack backtrace:
   0:     0x7f09a7897ee9 - <<std[89f22c552bc5066a]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[8ad6c24798842d79]::fmt::Display>::fmt
   1:     0x7f09a801b108 - core[8ad6c24798842d79]::fmt::write
   2:     0x7f09a78aeb06 - <std[89f22c552bc5066a]::sys::stdio::unix::Stderr as std[89f22c552bc5066a]::io::Write>::write_fmt
   3:     0x7f09a786df2e - std[89f22c552bc5066a]::panicking::default_hook::{closure#0}
   4:     0x7f09a788b5a3 - std[89f22c552bc5066a]::panicking::default_hook
   5:     0x7f09a676c511 - std[89f22c552bc5066a]::panicking::update_hook::<alloc[eb280b9ba06e18cf]::boxed::Box<rustc_driver_impl[234634a74b90a67c]::install_ice_hook::{closure#1}>>::{closure#0}
   6:     0x7f09a788b882 - std[89f22c552bc5066a]::panicking::panic_with_hook
   7:     0x7f09a786dff2 - std[89f22c552bc5066a]::panicking::panic_handler::{closure#0}
   8:     0x7f09a7864cf9 - std[89f22c552bc5066a]::sys::backtrace::__rust_end_short_backtrace::<std[89f22c552bc5066a]::panicking::panic_handler::{closure#0}, !>
   9:     0x7f09a786fa5d - __rustc[75ff3fde40943ffb]::rust_begin_unwind
  10:     0x7f09a4afc16c - core[8ad6c24798842d79]::panicking::panic_fmt
  11:     0x7f09a537ff64 - core[8ad6c24798842d79]::option::expect_failed
  12:     0x55b583bcbc55 - rustdoc[d2f483044280a0b2]::passes::collect_trait_impls::collect_trait_impls
  13:     0x55b583b6ec6a - rustdoc[d2f483044280a0b2]::core::run_global_ctxt
  14:     0x55b583a88371 - rustdoc[d2f483044280a0b2]::main_args::{closure#2}::{closure#0}
  15:     0x55b583a80b2e - rustc_interface[e735d0cf28bd6984]::interface::run_compiler::<(), rustdoc[d2f483044280a0b2]::main_args::{closure#2}>::{closure#1}
  16:     0x55b5839b70e6 - std[89f22c552bc5066a]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[e735d0cf28bd6984]::util::run_in_thread_with_globals<rustc_interface[e735d0cf28bd6984]::util::run_in_thread_pool_with_globals<rustc_interface[e735d0cf28bd6984]::interface::run_compiler<(), rustdoc[d2f483044280a0b2]::main_args::{closure#2}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  17:     0x55b583ac5ecd - <std[89f22c552bc5066a]::thread::lifecycle::spawn_unchecked<rustc_interface[e735d0cf28bd6984]::util::run_in_thread_with_globals<rustc_interface[e735d0cf28bd6984]::util::run_in_thread_pool_with_globals<rustc_interface[e735d0cf28bd6984]::interface::run_compiler<(), rustdoc[d2f483044280a0b2]::main_args::{closure#2}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[8ad6c24798842d79]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  18:     0x7f09a913ba2c - <std[89f22c552bc5066a]::sys::thread::unix::Thread>::new::thread_start
  19:     0x7f09a289697a - <unknown>
  20:     0x7f09a291a2bc - <unknown>
  21:                0x0 - <unknown>

error: the compiler unexpectedly panicked. This is a bug

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md

note: please make sure that you have updated to the latest nightly

note: please attach the file at `/home/matthias/vcs/github/CRED/rustc-ice-2026-05-12T05_30_01-3512748.txt` to your bug report

note: rustc 1.97.0-nightly (64a965e90 2026-05-11) running on x86_64-unknown-linux-gnu

query stack during panic:
end of query stack
warning: 1 warning emitted